Airships have long been known and used as a means of conveyance, surveillance, and entertainment. In one common form of an airship, an elongate ellipsoidal shaped bladder is used to suspend a gondola housing crew, equipment, etc., thereunder. This airship is a non-rigid lighter than air craft commonly referred to as a “blimp.” Although previously developed airships are effective in accomplishing their intended purpose, they are not without their problems. For instance, in ellipsoidal airships, many attachment mechanisms are coupled to the exterior of the ellipsoidal lift bladder to couple the lifting force of the bladder to the gondola. These attachment mechanism increase the drag of the airship, thus decreasing its efficiency.
Further, propulsion sources are exposed to the main air stream, thus increasing drag. Further still, the airship has a horizontally oriented lifting bladder defining a large footprint. Such a large footprint increases storage costs and the potential for an accident, as well as increasing landing and takeoff area space requirements. Inasmuch as the lifting bag is horizontally oriented, large forces are required to turn the airship since the horizontal arrangement of the lifting bladder increases the moment of inertia of the airship about a vertical axis. Thus, larger control surfaces, which develop large amounts of drag, are needed. Further, steerage is sluggish due to the large moment of inertia.
In the ellipsoidal airship, altitude changes are instigated by manipulating the pitch of the airship. For instance, to rise in altitude, the bow of the airship is elevated relative to the stern, thus providing a tilted attitude of the airship, causing an awkward and uncomfortable environment onboard the airship. Ellipsoidal airships also use semi-rigid to rigid lift bladder designs that are heavy and expensive, wherein loss of balloon pressure often causes severe safety issues. Further, the propulsion sources are often located adjacent to or attached to the gondola. This causes significant safety concerns for manned gondolas, and exposes any occupants to unpleasant noise and vibration.
Also, in ellipsoidal airships, the outer skin is typically laminated to enhance the rigidity of the outer skin and to aid in retaining the lifting gas therein. This results in a heavy and expensive outer skin. Further still, previously developed airships only use a single lifting bladder, causing significant safety issues should the single lifting bladder become punctured. Further, the breakdown of the airship requires the dumping of the lifting gas from the lifting bladder, since the lifting bladder is non-removably attached to the gondola. Also, if the propulsion fails in the previously developed ellipsoidal airship, steerage is lost and the airship will drift at the whims of the wind, an inherently dangerous situation.